Folding outer mirror

ABSTRACT

The object of this invention is to provide a folding outer mirror, in which the cost reduction, the prevention of large sizes and heavy weights, and higher stiffness of the stopper mechanism can be obtained. The folding outer mirror includes a mirror base extending outside from a side surface of vehicle body, a mirror assembly attached rotatably to the mirror base, and a stopper mechanism for stopping the mirror assembly at a predetermined position. The stopper mechanism is provided with a base-side engaging surface formed in the mirror base, and a body-side engaging surface formed in the mirror assembly and being in plane contact with the base-side engaging surface at a predetermined position. The base-side engaging surface and the body-side engaging surface are formed such that a raising angle relative to a rotating direction of the mirror assembly becomes a sharp angle.

FIELD OF THE INVENTION

The present invention relates to a folding outer mirror providing with arotatable mirror assembly mounted in the side of vehicle body.

BACKGROUND OF THE INVENTION

As an outer mirror attached to the side of vehicle body, it is, ingeneral, adapted to use a folding outer mirror, which is rotated betweena normal position to direct a mirror surface of a mirror approximatelyat a right angle relative to the side of vehicle body and a foldedposition to be folded in the side of vehicle body. In the foldedposition, the mirror surface is, in general, arranged to direct a rearposition opposing to the side of vehicle body by rotating the mirrorassembly in a direction of vehicle body. The folding outer mirror isconstituted to rotate to a forward retracted position prepared foroutside forces such as an unexpected crash or contact from the rear sideof car such that the mirror assembly can be retracted by rotating in theforward.

The folding outer mirror is provided with a mirror base extendingoutside from the side surface of vehicle body and a mirror assemblybeing rotatably mounted in the mirror base. The folding outer mirror isprovided with a positioning mechanism to stop the mirror assembly at anormal position and a stopper mechanism to stop the mirror assembly at afolded position or a retracted position when the mirror assembly rotatesfrom the normal position to a rear folded position or a forwardretracted position.

The stopper mechanism is constituted to compose, for example, of anarcuate groove formed in the mirror base and a convex part provided inthe mirror assembly and to move the convex part along the arcuategroove. For example, it may be referred to Japanese Patent unexaminedlaid-open publication No. 9806 of 2004 or No. 282088 of 2006. In such astopper mechanism, when the mirror assembly is folded in a foldedposition, one side end surface of the convex part (an engaging surface)is in contact with a circumferential end surface (an engaging surface)of the arcuate groove, thus to regulate a movement of the mirrorassembly. When the mirror assembly is rotated to a retracted position,the other side end surface of the convex part (an engaging surface) isin contact with the other end (an engaging portion), thus to regulate amovement of the mirror assembly. As above mentioned, when the foldingouter mirror is rotated rearwards or forwards from a normal position,the folding outer mirror is designed to stop at a folded position or aretracted position by contacting each side end surface of the convexpart with one end or the other end of the arcuate groove. The engagingsurface as contacted and engaged with each other is formed on a planecrossing at a right angle relative to a rotating direction of the mirrorassembly.

SUMMARY OF THE INVENTION

When the mirror assembly rotates to a retracted position, large forcecaused by unexpected crash or contact may be urged to an arcuate grooveformed in the mirror base and a convex part provided in the mirrorassembly. Thus, the arcuate groove and the convex part are required tohave a high stiffness. In conventional folding outer mirrors, thearcuate groove and the convex part are composed of high-intensitymaterials such as metal or plastics containing glass fiber in order tohave the predetermined stiffness as required. As a result, conventionalfolding outer mirrors may result in an increase in cost. Then, it isconsidered to require a large contact area between the large convex partand the arcuate groove so as to have the stiffness as required withouthigh-intensity materials. In this case, it results in large sizes andheavy weights of the folding outer mirror, as the stopper mechanismbecomes too large.

Accordingly, an object of the present invention is to provide a foldingouter mirror having the desired cost reduction, the prevention of largesizes and heavy weights, and the high stiffness of the stoppermechanism.

The invention according to Claim 1 invented so as to solve the aboveproblem is a folding outer mirror, which includes a mirror baseextending outside from the side surface of vehicle body, a mirrorassembly attached rotatably to the mirror base, and a stopper mechanismfor stopping the mirror assembly at a predetermined position. Then, itis characterized in that the stopper mechanism comprises a base-sideengaging surface formed in the mirror base, and a body-side engagingsurface formed in the mirror assembly and being in plane contact withthe base-side engaging surface at a predetermined position. Furthermore,the base-side engaging surface and the body-side engaging surface areconstituted such that a raising angle relative to a rotating directionof the mirror assembly is a sharp angle.

“A rotating direction of the mirror assembly” in the invention means atangential direction at any point in a rotating circumferentialdirection. “A raising angle” means an angle raising the engaging surfacedirecting from one side to the other side of the mirror base and themirror assembly, and an angle formed in the solid side of the engagingsurface relative to the rotating direction.

According to the above constitution, the force acting directly on plane,which is perpendicular to the engaging surface, becomes smaller than theoutside force urged in the rotating direction, and the contact areabetween the engaging surfaces is larger compared with the case where theengaging surface poses at a right angle relative to the rotatingdirection. That is, as the contact pressure in the contact surface issmall, the same or similar effect to increase the stiffness of themirror base and the mirror assembly can be obtained. Furthermore, as anangle of the member forming the engaging surface relative to therotating direction becomes an obtuse angle by making the raising anglefrom the rotating direction of the engaging surface to be a sharp angle,the stress concentration factor is greatly improved and the stressconcentration can be prevented. Therefore, the stopper mechanism havinga high degree of stiffness can be obtained without using high-intensitymaterial and the cost reduction thereof can be also obtained.Furthermore, as the engaging surface itself is not required to be large,large sizes and heavy weights of the stopper mechanism can be prevented.

The invention relating to Claim 2 is characterized by the followingelements on the basis of the folding outer mirror as described in Claim1. That is, the predetermined position is two positions, that is, at thefolded position and at the retracted position of the mirror assembly,and the base-side engaging surface and the body-side engaging surfaceare respectively formed to have two surfaces.

in such a constitution, in the folded position and the retractedposition receiving a comparatively large stress caused by outside forcessuch as an unexpected crash or contact, the higher stiffness of themirror base and the mirror assembly can be obtained. Accordingly, it iseffective and advantageous therein.

The invention relating to Claim 3 is characterized by the followingelements on the basis of the folding outer mirror as described in Claim1 or 2. That is, the mirror base is provided with the base-side arcuategroove having the same center as a rotation center of the mirrorassembly, and the mirror assembly is provided with the body-side convexpart inserting in the base-side arcuate groove. Further, the base-sideengaging surface is constituted to have a circumferential end surface ofthe base-side arcuate groove, and the body-side engaging surface isconstituted to have an end surface in a rotating direction of thebody-side convex part.

In such a constitution, as a thick-wall part can be obtained in the backof the base-side engaging surface by providing the base-side arcuategroove in the mirror base, the stiffness thereof can be further improvedto be higher.

The invention relating to Claim 4 is characterized by the followingelement on the basis of the folding outer mirror as described in Claim3. That is, the body-side convex part is integrally formed to have astiffening rib extending in a circumferential direction.

In such a constitution, as the body-side convex part itself becomeshigher in stiffness as a single unit of the body-side convex partitself, still higher stiffness of the stopper mechanism can be obtained.

The invention relating to Claim 5 is characterized by the followingelements on the basis of the folding outer mirror as described in Claim1 or 2. That is, the mirror base is provided with the base-side convexpart, the mirror assembly is provided with the body-side convex partengaged with the base-side convex part. Furthermore, the base-sideengaging surface is constituted at an end surface in a rotatingdirection of the mirror assembly of the base-side convex part, and thebody-side engaging surface is constituted at an end surface in arotating direction of the body-side convex part.

In such a constitution, a higher stiffness of the stopper mechanism canbe obtained by a comparatively simple constitution.

The invention relating to Claim 6 is characterized by the followingelements on the basis of the folding outer mirror as described in Claim1. That is, in the folding outer mirror comprising the mirror baseextending outside from the side surface of vehicle body and the mirrorassembly attached rotatably to the mirror base, the mirror base isprovided with the base-side arcuate groove having the same center as arotation center thereof, the mirror assembly is provided with thebody-side convex part inserted in the base-side arcuate groove, themirror assembly is provided with the body-side arcuate groove having thesame center as a rotation center thereof, and the mirror base isprovided with the base-side convex part inserted in the body-sidearcuate groove. Furthermore, the base-side engaging surface isconstituted at a circumferential end surface of the base-side arcuategroove and an end surface in a rotating direction of the mirror assemblyof the base-side convex part, the body-side engaging surface isconstituted at an end surface in a rotating direction of the body-sideconvex part and a circumferential end surface of the body-side arcuategroove. Then, when the mirror assembly is positioned at a rearwardfolded position or a forward retracted position, the body-side convexpart is in contact with the circumferential end surface of the base-sidearcuate groove, and the base-side convex part is in contact with thecircumferential end surface of the body-side arcuate groove.

In such a constitution, as the body-side convex part is in contact witha circumferential end of the base-side arcuate groove and the base-sideconvex part is in contact with a circumferential end of the body-sidearcuate groove, the contact area between the convex part and the arcuategroove can be made to be larger. Accordingly, as the outside force urgedto the mirror assembly is dispersed at the convex part and the arcuategroove, the higher stiffness of the stopper mechanism composing of theconvex part and the arcuate groove can be obtained without usinghigh-intensity materials, and the cost reduction thereof can beobtained. As the convex part is not required to be large as its singleunit, large sizes of the stopper mechanism composing of the convex partand the arcuate groove can be prevented, and heavy weights thereof canbe also prevented.

The invention relating to Claim 7 is characterized by the followingelements on the basis of the folding outer mirror as described in Claim6. That is, at least one of a combination of the body-side convex partand the base-side arcuate groove and a combination of the base-sideconvex part and the body-side arcuate groove are provided as a pluralityof combinations.

In such a constitution, as the contact area between the convex part andthe arcuate groove can be made to be larger, still further higherstiffness of the stopper mechanism can be obtained.

The invention relating to Claim 8 is characterized by the followingelement on the basis of the folding outer mirror as described in Claim7. That is, at least one of the body-side convex part and the base-sideconvex part is integrally provided with the stiffening rib extending ina circumferential direction.

In such a constitution, as the stiffness of the convex part itself as asingle unit is made to be higher, the further higher stiffness of thestopper mechanism can be obtained.

According to the present invention, it is effective and advantageous toprovide a folding outer mirror in which the cost reduction, theprevention of large sizes and heavy weights, and the higher stiffness ofthe stopper mechanism can be obtained.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is an exploded perspective view showing a folding outer mirrorrelating to a first embodiment of the present invention.

FIG. 2A is a plan view showing a positional relationship between eachconvex part and each arcuate groove in a normal position of the mirrorassembly of the folding outer mirror relating to the first embodiment ofthe present invention. FIG. 2B is a developed view in section takenalong a line ii-ii in FIG. 2A.

FIGS. 3A and 3B are views showing the folding outer mirror relating tothe first embodiment of the present invention. FIG. 8A is a plan viewshowing a positional relationship between each convex part and eacharcuate groove in a folded position of the mirror assembly. FIG. 3B is aplan view showing a positional relationship between each convex part andeach arcuate groove in a retracted position of the mirror assembly.

FIG. 4 is a sectional view showing a contact condition between abody-side convex part and a base-side arcuate groove of the foldingouter mirror relating to the present invention.

FIGS. 5A and 5B are views showing a comparative example of the contactcondition between the body-side convex part and the base-side arcuategroove of the folding outer mirror relating to the present invention.FIG. 5A is a sectional view showing a sectional view in case of aright-angled condition of the raising angle. FIG. 5B is a sectional viewshowing in case of an obtuse angle of the raising angle.

FIG. 6 is a perspective view showing the other form of the body-sideconvex part.

FIG. 7 is a perspective view showing a FEM analysis model.

FIG. 8 is a graph showing a relationship between the raising angle and amaximum principal stress.

FIGS. 9A, 9B and 9C are graphs showing a relationship between theraising angle and maximum principal stress influenced by depending onbeing with or without a stiffened rib. FIG. 9A is a graph showing aninside condition of the engaging surface, FIG. 9B is a graph showing anoutside condition of the engaging surface, and FIG. 9C is a graphshowing a deepside condition of the engaging surface.

FIGS. 10A and 10B are graphs showing a relationship between the raisingangle and the raising force of body. FIG. 10A is a graph showing thefolding torque in case of 60 Nm. FIG. 10B is a graph showing the foldingtorque in case of 30 Nm.

FIG. 11 is an exploded perspective view showing a folding outer mirrorrelating to a second embodiment of the present invention.

FIG. 12A is a side view showing the body-side engaging surface and thebase-side engaging surface of the folding outer mirror relating to thesecond embodiment of the present invention. FIG. 12B is a substantialenlarged side view.

FIG. 13 is an exploded perspective view showing a folding outer mirrorrelating to a third embodiment of the present invention.

FIG. 14A is a sectional view showing the body-side engaging surface andthe base-side engaging surface relating to the third embodiment of thepresent invention. FIG. 14B is a substantial enlarged sectional view.

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of a folding outer mirror relating to the presentinvention will be described in detail with respect to the attacheddrawings. In this embodiment, it will be given an example of an electricfolding outer mirror, which is adapted to rotate the mirror assemblywith electricity.

As shown in FIG. 1, the folding outer mirror 1 relating to thisembodiment is provided with a mirror base 10 extending from the sidesurface of vehicle body (as not shown) toward the side and a mirrorassembly 30 as been rotatably attached to the mirror base 10. The mirrorassembly 30 is constituted such that a mirror as not shown, a holder (asnot shown) holding the mirror, a frame (as not shown) holding the holderslantably, and an electric folding outer mirror (as not shown) rotatingthe mirror assembly 30 are housed in the mirror housing 31.

The electric folding outer mirror is provided with a shaft (as notshown) extending in an appropriately up-and-down direction and a motor(as not shown) rotating the mirror assembly 30 around the shaft. Theshaft is attached to a mounting scat of the mirror base 10 at its lowerextremity. The mirror assembly 30 is adapted to rotate between a normalposition P1 (as shown in FIG. 2) as developed outside and a foldedposition P2 (as shown in FIG. 3A) as folded inside by rotating aroundthe shaft through various gears (as not shown). The folding outer mirror1 is constituted to have a forward retracted position P3 (as shown inFIG. 3B) so as to retract the mirror assembly 30 by forward rotations inpreparation for outside forces such as unexpected crash or contact fromthe rear side of a vehicle body.

The mirror base 10 is provided with a mounting plate 12 fixed in amounting seat (as not shown) formed in a pillar portion or the likepositioned in a side door of vehicle body and a base body 13 extendingfrom the lower part of the mounting plate 12 toward a side direction.The mounting plate 12 and the base body 13 are integrally constituted bysynthetic plastic or the like. The mounting seat 11 of the shaft of anelectric folding unit is formed on the base body 13. The mounting seat11 is formed to have a plurality of bolt holes 11 a. Then, a bolt (asnot shown) is screwed on a boss of shaft through the bolt hole 11 a fromthe lower part of the base body 13, then to fix the shaft therein.

A crutch mechanism (as not shown) is provided between the shaft and theframe. The crutch mechanism is designed to position the mirror assembly30 between the normal position P1 (as referred to FIG. 2) and the foldedposition P2 (as referred to FIG. 3A) by regulating the rotation thereof.Also, the crutch mechanism is designed to accept the rotation to theretracted position P3 (as referred to FIG. 3B) of the mirror assembly 30at the time when outside forces such as unexpected crash or contact isurged from the rear side of vehicle body.

The folding outer mirror 1 is provided with a stopper mechanism 2 forstopping the mirror assembly 30 at the folded position P2 or theretracted position P3 when the mirror assembly 30 rotates from thenormal position P1 to the rearward folded position P2 or the retractedposition P3.

The stopper mechanism 2 is provided with base-side engaging surfaces 51a, 51 b formed in the mirror base 10 and body-side engaging surfaces 53a, 53 b being in a plane contact with the base-side engaging surfaces 51a, 51 b at the predetermined position (the folded position P2 or theretracted position P3) formed in the mirror assembly 30. In the foldedposition P2, the base-side engaging surface 51 a and the body-sideengaging surface 53 b are in plane contact with each other in a plane.In the retracted position P3, the base-side engaging surface 51 b andthe body-side engaging surface 53 b are in contact with each other. Thebase-side engaging surfaces 51 a, 51 b and the body-side engagingsurfaces 53 a, 53 b are constituted such that the raising angles thereofbecome an acute angle (as referred to FIG. 4) relative to a rotatingdirection D of the mirror assembly 30. The rotating direction D means atangential direction at any point of rotational circumferentialdirection in the above. The raising angle θ is an angle raising anengaging surface from the side of the mirror base 10 or the mirrorassembly 30 toward the other side on the basis of rotating direction,and means an angle in the solid side of the engaging surface relative tothe rotating direction D.

In this embodiment, the stopper mechanism 2 is constituted that thebase-side arcuate groove 14 is coaxially formed to have the same centeras a rotation center of the mirror assembly 30 in the mirror base 10 andthe body-side convex part 33 inserted into the mirror assembly 30 isprovided in the base-side arcuate groove 14. The body-side arcuategroove 35 is formed in the mirror assembly 30 in the same rotationcenter as the mirror assembly 30. The base-side convex part 16 insertedinto the body-side arcuate groove 35 is provided in the mirror base 10.When the mirror assembly 30 is at the rearward folded position P2 or theforward retracted position P3, the body-side convex part 33 is adaptedto be in contact with the circumferential end 14R (at a position of thefolded position P2) or 14L (at a position of the retracted position P3)of the base-side arcuate groove 14. The base-side convex part 16 is incontact with the circumferential end 35 aL (35 bL) (at a folded positionP2) or 35 aR (35 bR) (at a retracted position P3) of the body-sidearcuate groove 35. As later described, the right end surface 33R and theleft end surface 33L, as being surfaces of the both ends of thebody-side convex part 33, is slantingly formed such that the raisingangle θ becomes an acute angle. The circumferential end 14R or 14L ofthe base-side arcuate groove 14, as being in contact with thecircumferential end surface 33R, 33L of the body-side convex part 33, isslantingly formed such that the raising angle θ becomes an arcuateangle. The left end surface 33L of the body-side convex part 33 isconstituted to be the body-side engaging surface 53 b and thecircumferential end 14L of the base-side arcuate groove 14 isconstituted to be the base-side engaging surface 51 b. The right endsurface 33R of the body-side convex part 33 is constituted to be thebody-side engaging surface 53 a and the circumferential end 14R of thebase-side arcuate groove 14 is constituted to be the base-side engagingsurface 51 a.

Hereinafter, a constitution of the stopper mechanism 2 will be describedin detail. As shown in FIGS. 1 and 2, the base-side arcuate groove 14 isformed in the surrounding of the mounting seat 11 arranged on the uppersurface of the base body 13 of the mirror base 10. The base-side arcuategroove 14 is coaxially formed in a center of the shaft, that is, arotation center of the mirror assembly 30. The base-side arcuate groove14 is farmed at two positions on the concentric circle. Each of thebase-side arcuate grooves 14, 14 is arranged to grasp an intermediateportion 15 to form the predetermined narrow central angle therebetween.Both are mutually formed not to interfere with each other. As shown inFIG. 2, the base-side arcuate groove 14 is constituted to have a centralangle composed of a rotation angle A (the rearward folding angle)ranging from a normal position P1 to a folded position P2 (as referredto FIG. 3A), a rotation angle B (the forward folding angle) ranging froma normal position P1 to a retracted position P3 (as referred to FIG.3B), and a rotation angle C equivalent to a circumferential length ofthe body-side convex part 33 (a length in the rotating direction of themirror assembly 30) as described later. In this embodiment, the centralangle of the base-side arcuate groove 14 is a little smaller than 120degrees.

As shown in FIG. 1, a through hole 34 for inserting the shaft is formedon the lower surface 32 opposite to the mounting seat 11 of the mirrorhousing 31 of the mirror assembly 30. The through hole 34 has the samecircular form as the mounting seat 11. The body-side convex part 33 asinserted into the base-side arcuate groove 14 is provided in thesurrounding of the through hole 34. The body-side convex part 33 isconstituted to extend from the lower surface 32 of the mirror housing 31to the lower side. Two body-side convex parts 33 is coaxially providedand each of the body-side convex part 33, 33 is inserted into each oftwo base-side arcuate groove 14, 14. The body-side convex part 33 isconstituted by the same material such as synthetic plastics to beintegrally formed with the mirror housing 31.

As shown in FIG. 2A, when the mirror assembly 30 is positioned at anormal position P1, the right end surface 33R (as referred to FIG. 2B)(hereinafter, a left-and-right direction in this specification is astandard direction as seen from the rotation center at a conditionassembling the mirror assembly 30 and the mirror base 10) as seen fromthe rotation center of the body-side convex part 33 is adapted to be aposition spaced by a rotation angle A between the normal position P1 andthe folded position P2 from the right end surface 14R of the base-sidearcuate groove 14. At this time, the left end surface 33L (as referredto FIG. 2B) of the base-side arcuate groove 33 is positioned at aseparated position by a rotation angle B ranging between the normalposition P1 and the retracted position P3 from the left end surface 14Lof the base-side arcuate groove 14.

As shown in FIG. 1, FIG. 2B, and FIG. 4, the body-side convex part 33 isslantingly formed as the body-side convex part 33 such that the rightend surface 33R and the left end surface 83L, as being circumferentialboth ends, mutually approaches at the side of their lower extremity. Theright end surface 33R as being circumferential end surface of thebody-side convex part 33 is constituted to be the body-side engagingsurface 53 b and the left end surface 33L is constituted to be thebody-side engaging surface 53 a. The slanting angles (the raising angleθ relative to the rotating direction D) of the end surfaces 33R, 33L arerespectively equal and the right end surface 33R and the left endsurface 33L are mutually constituted in a shape of plane symmetry suchthat a line connecting between lower ends (lower extremities) of endsurfaces 33R, 33L constitutes a short side of isosceles trapezoid insection (as referred to FIG. 4). Although the body-side convex part 33is formed like a solid form, it is not limited thereto. It may be formedlike being a hollow form by emptying the internal portion thereof. Inthis way, light weight and cost reduction of the mirror assembly 30 canbe obtained. In FIGS. 2 and 3, the section of the body-side convex part33 as shown by hatchings shows a base and a horizontal section in a longside of trapezoid.

The right end surface 14R of the base-side arcuate groove 14 (asreferred to FIG. 2) slants at the same slanting angle (the raising angleθ relative to the rotating direction) as the right end surface 33R ofthe body-side convex part 33. As shown in FIG. 3A, when the mirrorassembly 30 is at a folded position P2, the right end surface 14R of thebase-side arcuate groove 14 and the right end surface 33R of thebody-side convex part 33 are mutually contacted in plane. The left endsurface 14L (as referred to FIG. 2B) of the base-side arcuate groove 14slants at the same slanting angle as the left end surface 331, of thebody-side convex part 33. As shown in FIG. 3B, when the mirror assembly30 is at the retracted position P3, the left end surface 14L of thebase-side arcuate groove 14 and the left end surface 33L of thebody-side convex part 83 are in contact with each other.

The body-side convex part 33 and the base-side arcuate groove 14 areconstituted as a combination (a combination of stoppers). Thecombination of stoppers is formed as two combinations.

As shown in FIG. 1 and FIG. 2A, 213, a pair of base-side convex parts16, 16 extending in the side of the mirror assembly 30 is formed on anupper surface of the base body 13 positioned at both ends in acircumferential direction of the base-side arcuate groove 14. Thebase-side convex part 16 is inserted into the body-side arcuate groove35 as later described. The base-side convex part 16 is constituted bythe same material such as synthetic plastics to be integrally formedwith the mirror base 10. The base-side convex part 16 (hereinafter, itmay be referred to as “base-side convex part 16 a”) formed in theintermediate part 15 positioned between the neighboring base-sidearcuate grooves 14, 14 is used as both the left end of one base-sidearcuate groove 14 and the right end of the other base-side arcuategroove 14. The base-side convex parts 16 are formed at three positions,that is, the right end of one base-side arcuate groove 14, the left endthereof (also use of the right end of the other base-side arcuate groove14), and the left end of the other base-side arcuate groove 14. Thesethree base-side convex parts 16, 16 a, 16 are formed in an equal pitchat the central angle of 120 degrees from the rotation center. Thebase-side convex part 16 a for both uses thereof is constituted that theboth circumferential ends are opposed to a pair of base-side arcuategrooves 14, 14, and the other base-side convex parts 16, 16 areconstituted that the only one circumferential end is opposed to thebase-side arcuate groove 14, 14.

In the base-side convex part 16 a formed in an intermediate partpositioning between the neighboring base-side arcuate grooves 14, 14,both of the circumferential end surfaces 16R, 16L slant at the sameslanting angle as the left end surface 14L and the right end surface 14Rof the base-side convex part 16 a respectively. As a result, thecircumferential end surface 16L of the base-side convex part 16 a andthe right end surface 14R of the base-side arcuate groove 14 lie on asame plane, and the circumferential end surface 16R of the base-sideconvex part 16 a and the right end surface 14R of the base-side arcuategroove 14 lie on a same plane. In the base-side convex part 16 (as shownin a middle and a left side of FIG. 2B) positioned at one end of thebase-side arcuate groove 14 and at the opposite end of the intermediatepart 15, the circumferential end surface 16R positioned in the side ofthe base-side arcuate groove 14 slants at the same slanting angle as theleft end surface 14L of the base-side arcuate groove 14. As a result,the circumferential end surface 16R of the base-side arcuate groove 14and the left end surface 14L of the base-side arcuate groove 14 lie on asame plane. The circumferential end surface in the reverse side of thecircumferential end surface 16R is formed to be orthogonal to an uppersurface of the base body 18 and to extend a vertical direction. In thebase-side convex part 16 (as shown in a middle and a right side of FIG.2B) positioned at the other base-side arcuate groove 14 and at theopposite end of the intermediate part 15, the circumferential endsurface 16L positioned in the side of the base-side arcuate groove 14slants at the same angle as the left end surface 14R of the base-sidearcuate groove 14. As a result, the circumferential end surface 16L ofthe base-side arcuate groove 14 and the right end surface 14R of thebase-side arcuate groove 14 lie on a same plane. The circumferential endsurface in the reverse side of the circumferential end surface 16L isformed to be orthogonal to an upper surface of the base body 13 and toextend a vertical direction.

The body-side arcuate groove 35 for inserting the base-side convex part16 is formed in the surrounding of the through hole 34 of the mirrorhousing 31 of the mirror assembly 30. The body-side arcuate groove 35 isformed to range like an arcuate curve between two body-side convex parts33, 33 at a narrow side and a wide side of central angle thereof. Thatis, the body-side arcuate groove 35 is constituted by the body-sidearcuate groove 35 a, 35 b, which are respectively long and short in thearcuate curves. Then, the body-side arcuate grooves 35 a, 35 b and thebody-side convex parts 33, 33 are constituted to form a circle, of whichcenter is a center of rotation of the mirror assembly 30. The base-sideconvex part 16 a having both use (the base-side convex part 16 a ofwhich the circumferential both ends are opposite to the base-sidearcuate grooves 14, 14) formed in the intermediate part 15 is insertedin the body-side arcuate groove 35 b as being short in the arcuatecurve, and the two base-side convex parts 16, of which only one of thecircumferential ends is opposed to the base-side arcuate groove 14, areinserted in the body-side arcuate groove 35 a as being long in thearcuate curve. A pair of the base-side convex parts 16, 16 positioned atboth ends of the base-side arcuate groove 14 are inserted in thebody-side arcuate groove 35 a as being long in the arcuate curve and thebody-side arcuate groove 35 b respectively. A pair of the base-sideconvex parts 16, 16 and a pair of the body-side arcuate grooves 35 a, 35b are adapted to constitute one combination (a stopper set). In thisembodiment, two sets of stopper sets are constituted.

As shown in FIG. 2B, the circumferential end surfaces 35 aL, 35 bL ofthe body-side arcuate grooves 35 a, 35 b slant at the same slantingangle as the right end surface 33R of each body-side convex part 33respectively. As a result, the circumferential end surfaces 35 aL, 35 bLof each body-side arcuate grooves 85 a, 35 b and the right end surfaces33R, 38R of each body-side convex part 33 lie on a same plane. Thecircumferential end surfaces 35 aR, 35 bR of each body-side arcuategrooves 35 a, 85 b slant at the same slanting angle as the left endsurface 33L of each body-side convex part 33. As a result, thecircumferential end surfaces 35 aR, 35 bR of each body-side arcuategrooves 35 a, 35 b and the left end surface 33L, 33L of each body-sideconvex part 33 lie on a same plane.

As shown in FIG. 2A, when the mirror assembly 30 is positioned at anormal position P1, the left end surface 35 aL of the body-side arcuategroove 35 a as being long in the arcuate curve (as referred to FIG. 2B)is positioned at a position spaced by the rotation angle A rangingbetween the normal position P1 and the folded position P2 from the leftend surface 16L of one base-side convex part 16 (as referred to FIG.2B), which only one end of the circumferential ends is opposed to thebase-side arcuate groove 14. At this time, the right end surface 35 aRof the body-side arcuate groove 35 a (as referred to FIG. 2B) as beinglong in the arcuate curve is positioned at a position spaced by therotation angle B ranging between the normal position P1 and theretracted position P3 from the right end surface 16R of the otherbase-side convex part 16 (as referred to FIG. 2B), which only one end ofthe circumferential ends is opposed to the base-side arcuate groove 14.

When the mirror assembly 30 is positioned at the normal position P1, theleft end surface 35 bL of the body-side arcuate groove 35 b as beingshort in the arcuate curve is positioned at a position spaced by therotation angle A ranging between the normal position P1 and the foldedposition P2 from the left end surface 16L of one base-side convex part16 (as referred to FIG. 2B) having two functions, which only one end ofthe circumferential ends is opposed to the base-side arcuate groove 14.At this time, the right end surface 35 bR of the body-side arcuategroove 35 b as being short in the arcuate curve is positioned at aposition spacing away the rotation angle B ranging between the normalposition 21 and the retracted position 23 from the right end surface 16Rof the base-side convex part 16 having two functions.

According to the embodiment as above mentioned, both a combination ofthe body-side convex part 33 and the base-side arcuate groove 14, and acombination of the base-side convex part 16 and the body-side arcuategroove 35 are respectively provided to have two sets to form a stoppermechanism 2.

Next, movements of each part of the folding outer mirror 1 asconstituted like the above will be described. As shown in FIG. 3A, whenthe mirror assembly 30 rotates to the folded position P2, the right endsurface 33R of the body-side convex part 33 (body-side engaging surface53 a) contacts the right end surface 14R of the base-side arcuate groove14 (base-side engaging surface 51 a) and the left end surface 35 bL ofthe body-side arcuate groove 35 b as being long in the arcuate curvecontacts the left end surface 16L of one base-side convex part 16, whichonly one end of the circumferential ends is opposed to the base-sidearcuate groove 14. In this embodiment, both a combination of thebody-side convex part 33 and the base-side arcuate groove 14, and acombination of the base-side convex part 16 and the body-side arcuategroove 35 are respectively provided to have two sets. Thus, the rightend surface 33R of the another pair of body-side convex part 33(body-side engaging surface 53 a) contacts the right end surface 14R ofthe base-side arcuate groove 14 ((base-side engaging surface 51 a), andthe left end surface 35 aL of the body-side arcuate groove 35 a as beingshort in the arcuate curve contacts the left end surface 16L of thebase-side convex part 16 having both functions.

Next, movements of each part of the folding outer mirror 1 asconstituted like the above will be described. As shown in FIG. 3B, whenthe mirror assembly 30 rotates to the retracted position P3, the leftend surface 33L of the body-side convex part 33 (body-side engagingsurface 53 b) contacts the left end surface 14L of the base-side arcuategroove 14 (base-side engaging surface 51 b) and the right end surface 35bR of the body-side arcuate groove 35 b as being long in the arcuatecurve contacts the left end surface 16L of one base-side convex part 16,which only one end of the circumferential ends is opposed to thebase-side arcuate groove 14. In this embodiment, both a combination ofthe body-side convex part 33 and the base-side arcuate groove 14, and acombination of the base-side convex part 16 and the body-side arcuategroove 35 are respectively provided to have two sets. Thus, the left endsurface 33L of the another pair of body-side convex part 33 (body-sideengaging surface 53 b) contacts the left end surface 14L of thebase-side arcuate groove 14 ((base-side engaging surface 51 a), and theleft end surface 35 aR of the body-side arcuate groove 35 a as beingshort in the arcuate curve contacts the right end surface 16R of thebase-side convex part 16 having both functions.

As above mentioned, according to this embodiment, the circumferentialends 33R, 33L (body-side engaging surfaces 53 a, 53 b) of the body-sideconvex part 33 are constituted to slant such that the raising anglerelative to the rotating direction D of the mirror assembly 30 becomesan acute angle, the circumferential ends 14R, 14L (base-side engagingsurface 51 a, 51 b) of the base-side arcuate groove 14 are constitutedto slant such that the raising angle relative to the rotating directionD of the mirror assembly 30 becomes an acute angle. Then, the stiffnessof the stopper mechanism 2 can be improved to enhance. This is based onthe following reason.

As shown in FIG. 4, when the right end surface 33R of the body-sideconvex part 33 contacts the right end surface 14R of the base-sidearcuate groove 14, the outside force urged to the body-side convex part33 is divided into a force acting directly on plane F1=F·sin θperpendicular to the right end surface 33R of the body-side convex part33, and a separate force in the slipping direction F2=F·cos θ. The forceacting directly on plane F1 urged to the right end surface 33R of thebody-side convex part 33 becomes smaller than the outside force F, andthe end surface of the contact area is larger than one in case of aright angle. Then, the plane pressure in the contact surface becomessmall, and functions toward an advantageous direction relative to astiffness of the body-side convex part 33. As a shearing length L of thebody-side convex part 33 becomes longer than one in case of a rightangle, the shearing intensity of the body-side convex part 33 becomesstronger. As an angle of the base part of the body-side convex part 33becomes an obtuse angle, and a stress concentration coefficient can begreatly improved and prevented a concentration of stress. The stressconcentration coefficient can be improved in case of a thick base part.When the arising angle θ relative to a horizontal plane of thecircumferential end 33L, 33R of the body-side convex part 33 is small,the force running on along the right end surface 14R or the left endsurface (as not shown) of the base-side arcuate groove 14 becomes large.In this case, the slanting angle θ is designed to set a larger valuethan the predetermined angle, at which the body-side convex part 33 doesnot run on relative to the right end surface 14R or left end surface (asnot shown). In such a constitution, the mirror assembly 30 is definitelyengaged at the predetermined position (a folded position P2 or retractedposition P3), and never runs on the base member 13.

The above embodiment will be compared with a case where the raisingangles of the base-side engaging surface and the body-side engagingsurface are a right angle or an obtuse angle respectively.

As shown in FIG. 5A, when the raising angle 0₁ relative to a rotatingdirection D of the base-side engaging surface 51 c and the body-sideengaging surface 53 c is a right angle, the body-side engaging surface53 c of the body-side convex part 33 receives an outside force Fdirectly. Then, the force in this case is larger than one of the aboveembodiment, and the contact area is smaller than one of the aboveembodiment. Accordingly, this contact pressure of the abutting surfaceis larger than one of this embodiment. As a length Ll of the shearingforce of the body-side convex part 33 is shorter than one of thisembodiment, a shearing intensity of the body-side convex part 33 makesstronger. As a result, this embodiment is understood to be higher instiffness than a case where the raising angle 0₁ of each engagingsurface 51 c, 53 c is a right angle.

As shown in FIG. 5B, when the raising angle θ₂ relative to a rotatingdirection D of the base-side engaging surface 51 and the body-sideengaging surface 53 d is an obtuse angle, the body-side engaging surface53 d of the body-side convex part 33 receives an outside force Fseparated into a direct contact pressure F3=F·sin θ₂ perpendicular tothe body-side engaging surface 53 d and a separate force F4=F·cos θ₂ ina slipping direction. The direct contact pressure F3 as received on thebody-side engaging surface 53 d of the body-side convex part 33 issmaller than an outside force F, and the contact area is larger than oneof the case where the end surface thereof is a right angle. Thus, thecontact pressure of the contact area becomes smaller, and functions tobe an advantageous side relative to a stiffness of the body-side convexpart 33. As a length of shearing force of the body-side convex part 33becomes larger than one of the case where the end surface thereof is aright angle, the shearing intensity of the body-side convex part 33becomes stronger. Then, it functions to be an advantageous side relativeto a stiffness of the body-side convex part 33, even in a case where theraising angle θ₂ is an obtuse angle. However, as an angle of the base ofthe body-side convex part 33 becomes an obtuse angle, it results in aconcentration of the stress and a worse stress concentration coefficientcaused by a thinner base. As above mentioned, the above embodiment isunderstood to be higher in stiffness than the case where the raisingangle θ₂ of each engaging surface 51 c, 53 c is an obtuse angle.

Furthermore, compared with a case where a contact area between theconvex part and the arcuate groove is one spot, the abutting part can begreatly increasing and the contact area can be larger in conventionalstopper mechanism. More specifically, a combination of the base-sideconvex part 16 and the body-side arcuate groove 35 other than acombination of the body-side convex part 33 and the base-side arcuategroove 14 can increase a number of the abutting part without a change ofwhole plane section of the stopper mechanism 2. Further, as the both ofthe above combinations are respectively provided to have two sets, theabutting part can be still increasingly doubled.

As a result, as the outside force (rotating force) received on themirror assembly 30 is designed to disperse into the body-side convexpart 33, the base-side arcuate groove 14, the base-side convex part 16and the body-side arcuate groove 35, the stress per unit area receivedon each part can be made small. Thus, high stiffness and cost reductionof the stopper mechanism 2 can be obtained without high-intensitymaterial. As it is not required to be large sizes of the body-sideconvex part 33 and the base-side convex part 16, a large-scale tendencyof the stopper mechanism 2 or the folding outer mirror 1 can beprevented. Then, a heavy-weight tendency of the stopper mechanism 2 andthe folding outer mirror 1 can be prevented.

As shown in FIG. 6, it may be constituted to form a stiffening rib 37extending in circumferential both sides in the outer spherical side ofthe body-side convex part 33. The stiffening rib 37 is mounted uprightin a area positioned in an outer spherical side of the body-side arcuategroove 35 provided under a lower surface of the mirror housing 31, andis constituted by triangular plates as integrally formed together withthe mirror housing 31 and the body-side convex part 33. In such aconstitution, a stiffness of the body-side convex part 33 can be madehigher. The circumferential both sides of the body-side convex part 33as been a form of trapezoid may be provided with the same form ofstiffening rib.

Next, the result analyzed by FEM (finite element method) will bedescribed with respect to the base-side engaging surface 51 a, 51 b andthe body-side engaging surface 53 a, 53 b relating to the presentinvention.

As shown in FIG. 7, the FEM analysis model 100 is constituted by thebase member 110 and the body member 130. The base member 110 is providedwith the base-side convex parts 116, 116 formed in the base-side arcuategroove 114 and the circumferential both ends respectively. The rightcircumferential end 114R of the base-side arcuate groove 114 and theleft end 116L of the right base-side convex part 116 slant at a raisingangle of an obtuse angle relative to a rotating direction of the bodymember 130 to lie on the same plane, which constitutes the base-sideengaging surface 51 a. The left circumferential end part 114L of thebase-side arcuate groove 114 and the right end surface 116R of the leftbase-side convex part 116 lie on the same plane as opposed to thebase-side engaging surface 51 a, and then to be a form of planesymmetry, which constitutes the base-side engaging surface 51 b. Thebase-side arcuate groove 114 and the base-side convex parts 116, 116 areconstituted to provide one more set thereof in order to form a symmetryin placing astride a rotation center of the body member 130.

The body member 130 is provided with the body-side convex part 133 andthe body-side arcuate groove 135, 135 formed in left and right bothsides. The right end 133R of the body-side convex part 133 and the leftcircumferential end 135L (in the side of the body-side convex part 133)of the body-side arcuate groove 135 slant at the same raising angle ofobtuse angle relative to a rotating direction of the body member 130 soas to lie on the same plane, which constitutes the body-side engagingsurface 53 b. The left end 133L of the body-side convex part 133 and theright circumferential end 135R in the side of the body-side convex part133) of the body-side arcuate groove 135 lie on the same plane as placedon both sides of the body-side convex part 133 to form the same plane,which constitutes the body-side engaging surface 53 b. The body-sideconvex part 133 and the body-side arcuate groove 135, 135 areconstituted to be placed at both sides of the rotating center of thebody member 130 to be a form of symmetry and to form one more set.

With use of the above FEM analysis model 100, the FEM analysis has beenperformed at various conditions as to an inner side 101, an outer side102, and a deep side 103 of the body-side convex part 133.

At first, when the raising angle of engaging surface is appropriatelyset in a range between 50 degrees and 110 degrees, and a maximumprincipal stress received on an inner side 101, an outer side 102, andthe deep side 103 is analyzed, the result is shown in FIG. 8. In theinner side, the maximum principal stress decreases as the raising angledecreases. In the outer side, the maximum principal stress is a peak atan angle of 90 degrees, and decreases as the raising angle decreases. Inthe deep side, the maximum principal stress is a peak at an angle of 90degrees, decreases at an angle of 80 degrees, increases at an angle of70 degrees, and decreases at an angle of 50 degrees. In addition, themaximum principal stress is a minimum value at an angle of 110 degrees.

As above mentioned, in a range being a smaller than 90 degrees in theraising angle, it has been found that the maximum principal stress urgedon each part of the body-side convex part 133 decreases in general asthe raising angle decreases.

Next, when the raising angle of engaging surface is appropriately set ina range between 50 degrees and 90 degrees, the maximum principal stressurged on the inner side 101, the outer side 102, and the deep side 103of the body-side convex part 133 has been analyzed in case of being withand without the stiffening rib, the result shows in FIG. 9. As shown inFIG. 9A, although the maximum principal stress decreases a little in theinner side in case of having the stiffening rib, there are fewinfluences by the fact of with or without the stiffening rib. Inaddition, the maximum principal stress decreases in a range that theraising angle is less than or equal to 65 degrees in case of nostiffening rib. As shown in FIG. 9B, the maximum principal stress issmall in the outer side in case of having the stiffening rib. Then, itis greatly influenced by the fact whether the stiffening rib exists ornot. In addition, the maximum principal stress decreases in a range thatthe raising angle is less than or equal to 60 degrees in case of nostiffening rib. As shown in FIG. 9C, the maximum principal stressdecreases a little in the deep side in case of having the stiffeningrib. Then, it influences a few on the fact whether the stiffening ribexists or not. In addition, the maximum principal stress decreases in arange that the raising angle is less than or equal to 60 degrees in caseof no stiffening rib.

As above mentioned, it has found to obtain an advantageous effect thatthe maximum principal stress is small in the outer side of the body-sideconvex part 133 as the stiffening rib provided, compared with the casehaving no stiffening rib.

Next, the frictional force μ of the engaging surface is set to be [0.1],[0.2], and [0.3] as the folding torque F urged to the body member 130and the raising angle of the engaging surface is appropriately set in arange between 60 degrees and 90 degrees. Analyzing the rising forceurged to the body member 130, the result shown in FIG. 10 can beobtained.

The mirror assembly is ordinarily set in the mirror base to becompressed around a rotating axis with a coil spring. Then, when thestress to rise the body member 130 urged to the engaging surface is Fv,the raising force Fu urged to the body member 130 is represented by thefollowing equation (1).

Fu=Fs−Fv  equation (1)

Herein,

Fv=F·(cos 0−μ·sin θ)  equation (2)

Where F is a folding torque, 0 is a raising angle of the engagingsurface, and μ is a frictional force of the engaging surface.

and

Fu=≦0  equation (3)

The equation (3) is a condition (practical range) in which does notcause the mirror assembly to rise.

As shown in FIG. 10A, in case of 60 Nm of the folding torque F, the bodymember 130 runs on at 78 degrees or less of the raising angle when thefrictional force μ of the engaging surface is equal to 0.1, the bodymember 130 runs on at 73 degrees or less of the raising angle when thefrictional force μ is 0.2, and the body member 130 runs on at 67 degreesor less of the raising angle when the frictional force μ is 0.3.

As shown in FIG. 10B, in case of 30 Nm of the folding torque F, the bodymember 130 runs on at 73 degrees or less of the raising angle when thefriction force μ of the engaging surface is equal to 0.1, the bodymember 130 runs on at 66 degrees or less of the raising angle when thefrictional force is 0.2, and the body member 130 runs on at 60 degreesor less of the raising angle when the frictional force μ is 0.3.

Thus, in a form of a first embodiment, θ is preferable to be 67 degreesor more and less than 90 degrees in the raising angle when the africtional coefficient μ is 0.3. In this area, it can be satisfied withthe above equation (3), a stiffness of the mirror base and the mirrorhousing can be enhanced, and the running on of the mirror assembly canbe effectively prevented to exactly stop at the predetermined positionof the mirror assembly. A relative position's relationship in aup-and-down direction between the mirror assembly and the mirror basecan be maintained at a constant value.

Next, a second embodiment of the folding outer mirror relating to thepresent invention will be described with reference to FIG. 11 and FIG.12. The folding outer mirror of this embodiment is a manual foldingouter mirror.

As shown in FIG. 11, a folding outer mirror 201 relating to the secondembodiment has a mirror assembly providing a mirror base 210, a shaft220 standing upright at the mirror base 210, and a rotation frame 230rotating around the shaft 220 being a rotating axis.

A notch 232 is formed at a lower end of the cylindrical part 231surrounding the shaft 220. The notch 282 is designed to slant a littlein a rotating direction of the mirror assembly at one end side (leftside in FIG. 11) and to form a step portion to slant approximately at aright angle at the other end side (right side in FIG. 11). On the otherhand, the base-side convex part 211 extending in an upper direction inthe surrounding of the peripheral portion of the shaft 220 extends on anupper surface of the mirror base 210. One end surface 212 of thebase-side convex part 211 is engaged with an end surface 233 a of thestep portion 233 of the notch 232 of the rotation frame 230 at thepredetermined position such as a folded position, thus to stop therotation frame 230 at the predetermined position. In this embodiment thestopper mechanism 202 is constituted by the notch 232 of the rotationframe 230 and the base-side convex part 211 of the mirror base 210. Thebody-side engaging surface 253 is constituted by the end surface 233 aof the step portion 233 of the notch 232, and the base-side engagingsurface 251 is constituted by one end surface 212 of the base-sideconvex part 211.

As shown in FIG. 12, the end surface 233 a (the body-side engagingsurface 253) of the step portion 233 of the notch 232 is formed to slantsuch that the raising angle θ relative to the rotating direction D ofthe mirror assembly becomes a sharp angle. The one end surface 212 (thebase-side engaging surface 251) of the base-side convex part 211 isformed to slant such that the raising angle θ relative to the rotatingdirection D of the mirror assembly is a sharp angle (the same angle asthe raising angle of the body-side engaging surface 253).

In such a constitution, as shown in FIG. 12B, when the end surface 233 aof the step portion 233 of the notch 232 contacts the one end surface212 of the base-side convex part 211, an outside force F is divided intoa force acting direct on a plane (F1=F·sin θ) perpendicular to the endsurface 233 and a separate force in a slip direction F2=F·cos θ. Theforce acting direct on a plane Fl urged to the end surface 233 a issmaller than the outside force F, and the contact area of the endsurface is larger than one at the time of an right angle thereof.Accordingly, the contact pressure of the contact area is small, andfunctions as an advantageous side relative to a stiffness of the stepportion 233. Then, a stiffness of the stopper mechanism 202 becomeshigh.

Next, a third embodiment of the folding outer mirror relating to thepresent invention will be described with reference to FIG. 13 and FIG.14. The folding outer mirror of this embodiment is an electric foldingouter mirror.

As shown in FIG. 13, the folding outer mirror 301 relating to the thirdembodiment has a mirror assembly providing a mirror base 310, a shaft320 standing upright on the mirror base 310, and an electric foldingunit 330 rotating around the shaft 320 being a rotation axis. Thefeature of this embodiment is characterized in that the raisingdirection of the base-side engaging surface and the body-side engagingsurface of the first and second embodiments is up-and-down direction.While, the folding outer mirror of this embodiment is characterized inthat the raising direction of the base-side engaging surface and thebody-side engaging surface directs a radial direction of the rotation ofthe mirror assembly.

The body-side convex part 332 extending outside in the radial directionon an outside circumferential surface of a cylindrical part 331 isformed at a lower end of the cylindrical part 331 surrounding the shaft320 of the electric folding unit 330. As shown in FIG. 14A, thebody-side convex part 332 is formed like an arcuate curve in section torotate for opening at a predetermined angle. The center of the arcuatecurve in section is the same as rotation center of the mirror assembly.Both end surfaces 332R, 332L in the circumferential direction of thebody-side convex part 332 are respectively constituted to slant suchthat the raising angle 0 raising outside relative to the rotatingdirection D of the mirror assembly becomes a sharp angle. That is, thebody-side convex part 332 is constituted such that a length along theouter circumference is shorter than a length along the innercircumference. Then, the body-side engaging surface 353 is constitutedby both end surfaces 332R, 332L in the circumferential direction of thebody-side convex part 332.

The base-side convex part 311 extending an upper direction in thesurrounding of the circumferential edge of the shaft 320 is formed on anupper surface of the mirror base 310. The base-side convex part 311 isformed like an arcuate curve in section so as to surround thecylindrical part 331 of the electric folding unit 330. The center of thearcuate curve in section is the same as a rotation center of the mirrorassembly. The both end surfaces 311R, 311L of the base-side convex part311 is constituted to slant such that the raising angle θ raisinginwards relative to the rotating direction D of the mirror assemblybecomes a sharp angle (the same angle as the raising angle of thebody-side engaging surface 353). That is, the base-side convex part 311is constituted such that a length along the inner circumference isshorter than a length along the outer circumference. Then, the base-sideengaging surface 351 is constituted by the both end surfaces 311R, 311Lin the circumferential direction of the base-side convex part 311.

In such a constitution, as shown in FIG. 14B, when the end surface 332L(the body-side engaging surface 353) in the circumferential direction ofthe body-side convex part 332 contacts the end surface 311R (thebase-side engaging surface 351) in the circumferential direction of thebody-side convex part 332, an outside force F urged to the body-sideconvex part 311 is divided into a force acting direct on a planeF1=F·sin 0 perpendicular to the end surface 332L and a separate force ina slip direction F2=F·cos θ. The force acting direct on a plane Fl urgedto the end surface 332L is smaller than the outside force F, and thecontact area of the end surface is larger than one at the time of aright angle thereof. Accordingly, the contact pressure of the contactarea is small, and functions as an advantageous side relative to astiffness of the step portion 233. Then, a stiffness of the stoppermechanism 302 becomes high.

Although the embodiments for carrying out the present invention has beendescribed, the present invention is not limited to the above embodimentsand various modifications can be appropriately performed withoutdeparting from the spirit and the gist of the present invention

Although the above embodiments has been described by giving an exampleof an electric folding outer mirror rotating the mirror assembly withelectricity, it is not limited thereto. The manual folding outer mirrorfor manually rotating the mirror assembly is applicable in the presentinvention.

1. A folding outer mirror having a mirror base extending outside fromthe side surface of a vehicle body, a mirror assembly attached rotatablyto the mirror base, and a stopper mechanism for stopping the mirrorassembly at a predetermined position, wherein the stopper mechanismcomprises a base-side engaging surface formed in the mirror base, and abody-side engaging surface formed in the mirror assembly and being inplane contact with the base-side engaging surface at a predeterminedposition, and wherein the base-side engaging surface and the body-sideengaging surface are constituted such that a raising angle relative to arotating direction of the mirror assembly is a sharp angle.
 2. Thefolding outer mirror according to claim 1, wherein the predeterminedposition is two positions of a folded position and a retracted positionof the mirror assembly, and the base-side engaging surface and thebody-side engaging surface are respectively formed to have two surfaces.3. The folding outer mirror according to claim 1, wherein the mirrorbase is provided with the base-side arcuate groove having the samecenter as a rotation center of the mirror assembly, the mirror assemblyis provided with the body-side convex part inserting in the base-sidearcuate groove, the base-side engaging surface is constituted to have acircumferential end surface of the base-side arcuate groove, and thebody-side engaging surface is constituted to have an end surface in arotating direction of the body-side convex part.
 4. The folding outermirror according to claim 3, wherein the body-side convex part isintegrally formed to have a stiffening rib extending in acircumferential direction.
 5. The folding outer mirror according toclaim 1, wherein the mirror base is provided with the base-side convexpart, the mirror assembly is provided with the body-side convex partengaged with the base-side convex part, the base-side engaging surfaceis constituted at an end surface in a rotating direction of the mirrorassembly of the base-side convex part, and the body-side engagingsurface is constituted at an end surface in a rotating direction of thebody-side convex part.
 6. The folding outer mirror according to claim 1,wherein in the folding outer mirror having the mirror base extendingoutside from the side surface of vehicle body and the mirror assemblyattached rotatably to the mirror base, the mirror base is provided withthe base-side arcuate groove having the same center as a rotation centerof the mirror assembly, the mirror assembly is provided with thebody-side convex part inserted in the base-side arcuate groove, themirror assembly is provided with the body-side arcuate groove having thesame center as a rotation center thereof, the mirror base is providedwith the base-side convex part inserted in the body-side arcuate groove,the base-side engaging surface is constituted at a circumferential endsurface of the base-side arcuate groove and an end surface in a rotatingdirection of the minor assembly of the base-side convex part, thebody-side engaging surface is constituted at an end surface in arotating direction of the body-side convex part and a circumferentialend surface of the body-side arcuate groove, and when the mirrorassembly is positioned at a rearward folded position or a forwardretracted position, the body-side convex part is in contact with thecircumferential end surface of the base-side arcuate groove, and thebase-side convex part is in contact with the circumferential end surfaceof the body-side arcuate groove.
 7. The folding outer mirror accordingto claim 6, wherein a plurality of at least one of a combination of thebody-side convex part and the base-side arcuate groove, and acombination of the base-side convex part and the body-side arcuategroove are provided.
 8. The folding outer mirror according to claim 6,wherein at least one of the body-side convex part and the base-sideconvex part is provided with a stiffening rib extending in acircumferential direction.
 9. The folding outer mirror according toclaim 2, wherein the mirror base is provided with the base-side arcuategroove having the same center as a rotation center of the mirrorassembly, the mirror assembly is provided with the body-side convex partinserting in the base-side arcuate groove, the base-side engagingsurface is constituted to have a circumferential end surface of thebase-side arcuate groove, and the body-side engaging surface isconstituted to have an end surface in a rotating direction of thebody-side convex part.
 10. The folding outer mirror according to claim9, wherein the body-side convex part is integrally formed to have astiffening rib extending in a circumferential direction.
 11. The foldingouter mirror according to claim 2, wherein the mirror base is providedwith the base-side convex part, the mirror assembly is provided with thebody-side convex part engaged with the base-side convex part, thebase-side engaging surface is constituted at an end surface in arotating direction of the mirror assembly of the base-side convex part,and the body-side engaging surface is constituted at an end surface in arotating direction of the body-side convex part.
 12. The folding outermirror according to claim 7, wherein at least one of the body-sideconvex part and the base-side convex part is provided with a stiffeningrib extending in a circumferential direction.